The present invention relates to a device for coupling a heddle frame on a movement-transmission element of a weave system. The invention also relates to an assembly for driving the heddle frames, to a weaving loom incorporating such a device, and to a weaving loom equipped with such a device or such an assembly.
It is known to provide mechanical systems for connecting the frames of a weaving loom with rods or cables driven with a vertical oscillating movement by a weave system, particularly a dobby. EP-A-0 297 003 and EP-A-0 467 808 provide using elements forming tenon and mortise respectively, this allowing an efficient and rapid anchoring of the frame on the transmission element. However, such known devices present certain limitations.
The device of EP-A-0 297 003 provides a longitudinal adjustment of the tenon on a movement-transmission rod by adherence and wedging, thanks to wedde-shaped elements. In the event of poor clamping of these elements, a considerable risk of slide exists, which may lead to serious damage to the weaving loom, particularly by blockage of the frames and/or breakage of the connecting rods.
The device of EP-A-0 467 808 provides that the adjustment in height is of the micrometric type thanks to a tenon comprising a tapped central orifice, which avoids risks of untimely slide. However, this device is such that the surfaces of the tenon and mortise in contact are relatively small, while intense efforts are transmitted thanks to these surfaces, with considerable accelerations, hence a risk of premature wear of these surfaces by caulking.
It is a particular object of the present invention to overcome these drawbacks by proposing a novel coupling device in which a member forming tenon is secured with respect to a movement-transmission element, while the surfaces in contact of this tenon-forming element and of the mortise-forming element associated therewith are sufficiently large to withstand intense efforts.
To that end, the invention relates to a device for coupling a heddle frame on a movement-transmission element of a weave system, this device comprising a male member forming tenon mounted on the transmission element and a female member forming mortise fixed on an upright of the frame, the mortise member being provided with a central slot for passage of the transmission element and defining, on either side of this slot, contact surfaces intended to cooperate with the tenon member for transmission of the efforts, characterized in that the tenon member is formed by an assembly comprising:
a nut screwed on the transmission element;
an anchoring block forming at least two surfaces intended to cooperate with the contact surfaces of the mortise member, this block being provided with a through bore for passage of the transmission element and for reception, with possibility of rotation, of the nut,
a bush provided with a central bore for passage of the transmission element and adapted to drive the nut in rotation about the transmission element, through the bore of the block, and
a counter-nut for clamping the bush against the afore-mentioned block and nut.
Thanks to the invention, the dimensions of the block may be provided so that its surfaces intended to cooperate with the mortise member are relatively large, while the adjustment of the longitudinal position of the tenon member does not oblige the block to undergo a movement of rotation about the threaded rod constituting the transmission element, which would not be compatible with the usual density of implantation of the frames in a weaving loom. In other words, the nut and the bush make it possible to obtain adjustment of the position of the block along the transmisison element without inducing rotation of this block, the block thus being able to conserve a suitable orientation with respect to the mortise element borne by the frame.
According to advantageous aspects of the invention, the device incorporates one or more of the following characteristics:
The nut and the bush are provided with elements in relief of corresponding shapes allowing a claw coupling of the nut and the bush.
The bush is provided with a polygonal-section head, enabling it to be driven in rotation by means of a conventional spanner.
The bore of the block comprises two inner shoulders turned respectively towards the two openings of this bore and intended to cooperate respectively with corresponding surfaces of the nut and of the bush. These two inner shoulders make it possible to control the position of the block along the transmission element thanks to the nut and the bush.
The block is provided with at least one protuberance adapted to be engaged in the slot of the mortise member. This protuberance ensures a suitable positioning of the block with respect to the mortise member and to the environment of the frame.
The block is provided with an extension directed opposite the mortise member when the tenon member is in place in the mortise member, this extension being adapted to be engaged in a slideway for guiding and retaining the tenon member. In that case, this extension advantageously presents a transverse section substantially in the form of a T.
The invention also relates to an assembly for driving the heddle frames of a weaving loom, which comprises at least one device as described hereinbefore and a set of guides adapted each to receive an extension of the block of such a device, each guide presenting, in transverse section, a shape such that it opposes an extraction of the extension in a direction substantially perpendicular to the direction of slide of the extension in the guide in question. In addition, the guide may be provided to be mobile in a direction substantially perpendicular to the direction of slide, which makes it possible to control a movement of introduction/extraction of the tenon member with respect to the mortise member.
Finally, the invention relates to a weaving loom equipped with a device or an assembly as described hereinbefore. Such a loom is easier to use, particularly when frames are changed, which is a regular process during use of such a loom.